In the production of pneumatic tires for automotive vehicles a tire carcass is formed and usually built up with belts and the like and formed with the tire beads before the tire is then pressed in a vulcanizing press with heating. Such presses can have a bladder for holding the carcass or tire blank against the heated walls of the mold formed by the press. The blank or raw tire is positioned in the tire heating press which is then closed for the vulcanizing operation.
In general, a feeding and positioning apparatus for the tire bladder press is used to transfer the raw tire or blank into the mold of the press for vulcanization. In order to avoid any defective pressings, it is necessary to accurately center the raw tire within the mold.
From the German patent publication-open application DE-OS 1 804 097, corresponding to U.S. Pat. No. 3,620,561, such a transport system is known in which a swingable gripper is used which is provided with a plurality of axially symmetrical shovel-like gripping arms. These gripping arms seize the raw tires and transfers them from a bead-pressing device into the mold of the tire-heating or bladder press. Accordingly, this prior art uses the bead-pressing device as a raw tire stand so that the raw tire is centered with respect to the bead and clamped by the gripper from the outside.
Such bead pressing devices, however, are not suitable as stands where raw tires are built up and already prepared for vulcanization elsewhere. Moreover, practice has shown that the gripper was not always able to pick up, transfer and deposit the raw tire into the mold with the requisite degree of precision so that mispressing could result.